diff options
Diffstat (limited to 'drivers/net/phy/microchip_t1s.c')
| -rw-r--r-- | drivers/net/phy/microchip_t1s.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/drivers/net/phy/microchip_t1s.c b/drivers/net/phy/microchip_t1s.c new file mode 100644 index 000000000000..094967b3c111 --- /dev/null +++ b/drivers/net/phy/microchip_t1s.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Driver for Microchip 10BASE-T1S LAN867X PHY + * + * Support: Microchip Phys: + * lan8670, lan8671, lan8672 + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/phy.h> + +#define PHY_ID_LAN867X 0x0007C160 + +#define LAN867X_REG_IRQ_1_CTL 0x001C +#define LAN867X_REG_IRQ_2_CTL 0x001D + +/* The arrays below are pulled from the following table from AN1699 + * Access MMD Address Value Mask + * RMW 0x1F 0x00D0 0x0002 0x0E03 + * RMW 0x1F 0x00D1 0x0000 0x0300 + * RMW 0x1F 0x0084 0x3380 0xFFC0 + * RMW 0x1F 0x0085 0x0006 0x000F + * RMW 0x1F 0x008A 0xC000 0xF800 + * RMW 0x1F 0x0087 0x801C 0x801C + * RMW 0x1F 0x0088 0x033F 0x1FFF + * W 0x1F 0x008B 0x0404 ------ + * RMW 0x1F 0x0080 0x0600 0x0600 + * RMW 0x1F 0x00F1 0x2400 0x7F00 + * RMW 0x1F 0x0096 0x2000 0x2000 + * W 0x1F 0x0099 0x7F80 ------ + */ + +static const int lan867x_fixup_registers[12] = { + 0x00D0, 0x00D1, 0x0084, 0x0085, + 0x008A, 0x0087, 0x0088, 0x008B, + 0x0080, 0x00F1, 0x0096, 0x0099, +}; + +static const int lan867x_fixup_values[12] = { + 0x0002, 0x0000, 0x3380, 0x0006, + 0xC000, 0x801C, 0x033F, 0x0404, + 0x0600, 0x2400, 0x2000, 0x7F80, +}; + +static const int lan867x_fixup_masks[12] = { + 0x0E03, 0x0300, 0xFFC0, 0x000F, + 0xF800, 0x801C, 0x1FFF, 0xFFFF, + 0x0600, 0x7F00, 0x2000, 0xFFFF, +}; + +static int lan867x_config_init(struct phy_device *phydev) +{ + /* HW quirk: Microchip states in the application note (AN1699) for the phy + * that a set of read-modify-write (rmw) operations has to be performed + * on a set of seemingly magic registers. + * The result of these operations is just described as 'optimal performance' + * Microchip gives no explanation as to what these mmd regs do, + * in fact they are marked as reserved in the datasheet. + * It is unclear if phy_modify_mmd would be safe to use or if a write + * really has to happen to each register. + * In order to exactly conform to what is stated in the AN phy_write_mmd is + * used, which might then write the same value back as read + modified. + */ + + int reg_value; + int err; + int reg; + + /* Read-Modified Write Pseudocode (from AN1699) + * current_val = read_register(mmd, addr) // Read current register value + * new_val = current_val AND (NOT mask) // Clear bit fields to be written + * new_val = new_val OR value // Set bits + * write_register(mmd, addr, new_val) // Write back updated register value + */ + for (int i = 0; i < ARRAY_SIZE(lan867x_fixup_registers); i++) { + reg = lan867x_fixup_registers[i]; + reg_value = phy_read_mmd(phydev, MDIO_MMD_VEND2, reg); + reg_value &= ~lan867x_fixup_masks[i]; + reg_value |= lan867x_fixup_values[i]; + err = phy_write_mmd(phydev, MDIO_MMD_VEND2, reg, reg_value); + if (err != 0) + return err; + } + + /* None of the interrupts in the lan867x phy seem relevant. + * Other phys inspect the link status and call phy_trigger_machine + * in the interrupt handler. + * This phy does not support link status, and thus has no interrupt + * for it either. + * So we'll just disable all interrupts on the chip. + */ + err = phy_write_mmd(phydev, MDIO_MMD_VEND2, LAN867X_REG_IRQ_1_CTL, 0xFFFF); + if (err != 0) + return err; + return phy_write_mmd(phydev, MDIO_MMD_VEND2, LAN867X_REG_IRQ_2_CTL, 0xFFFF); +} + +static int lan867x_read_status(struct phy_device *phydev) +{ + /* The phy has some limitations, namely: + * - always reports link up + * - only supports 10MBit half duplex + * - does not support auto negotiate + */ + phydev->link = 1; + phydev->duplex = DUPLEX_HALF; + phydev->speed = SPEED_10; + phydev->autoneg = AUTONEG_DISABLE; + + return 0; +} + +static struct phy_driver lan867x_driver[] = { + { + PHY_ID_MATCH_MODEL(PHY_ID_LAN867X), + .name = "LAN867X", + .features = PHY_BASIC_T1S_P2MP_FEATURES, + .config_init = lan867x_config_init, + .read_status = lan867x_read_status, + .get_plca_cfg = genphy_c45_plca_get_cfg, + .set_plca_cfg = genphy_c45_plca_set_cfg, + .get_plca_status = genphy_c45_plca_get_status, + } +}; + +module_phy_driver(lan867x_driver); + +static struct mdio_device_id __maybe_unused tbl[] = { + { PHY_ID_MATCH_MODEL(PHY_ID_LAN867X) }, + { } +}; + +MODULE_DEVICE_TABLE(mdio, tbl); + +MODULE_DESCRIPTION("Microchip 10BASE-T1S lan867x Phy driver"); +MODULE_AUTHOR("Ramón Nordin Rodriguez"); +MODULE_LICENSE("GPL"); |